President Donald Trump has very publicly touted the benefits of hydroxychloroquine for the treatment of COVID-19, but a new study of U.S. veterans has actually shown increased mortality rates for patients treated with the antimalarial drug.
On March 20, French scientists published a study of 20 COVID-19-positive patients claiming treatment with hydroxychloroquine significantly reduced viral load, especially if azithromycin (an antibiotic) was added to the regimen. However, the study was open-label and not randomized, and subsequent studies have not been able to confirm the finding, including the veteran study just published.
The Veterans Health Administration-based study included 368 patients, the largest dataset yet reported. The veterans were assigned to three groups: those treated with hydroxychloroquine, those treated with hydroxychloroquine and azithromycin, or those treated with standard care (no medication).
The rate of death was highest in the hydroxychloroquine-treated group and lowest in the hydroxychloroquine-untreated group. About 28% of patients given hydroxychloroquine plus standard care died, versus 11% of patients who received routine care alone. About 22% of patients who were given hydroxychloroquine plus azithromycin died.
Hydroxychloroquine did not have any effect on the need for a ventilator. Ventilation occurred in 13% of those treated with hydroxychloroquine, 7% in the hydroxychloroquine plus azithromycin group, and 14% in the no hydroxychloroquine group.
While the study authors did not track side effects, they did note that the large high mortality rate in the patients treated with hydroxychloroquine could be attributable to drug effects, especially since there was no significant difference in ventilation rates.
Hydroxychloroquine has long been known to cause potentially serious heart side effects. Recently, for example, scientists in Brazil were forced to stop part of their study of chloroquine as a possible coronavirus treatment after heart rhythm problems developed in 25% of people given the higher of two doses being tested.
On Tuesday, the National Institutes of Health issued further guidance on the therapeutic options for COVID-19, specifically calling out hydroxychloroquine. The guidelines say there are insufficient clinical data to recommend the use of the antimalarial drug, but if it is used, the patient should be monitored very closely for an adverse reaction.
“The COVID-19 Treatment Guidelines Panel also recommends against the use of the combination of hydroxychloroquine plus azithromycin because of the potential for toxicities,” the NIH elaborated in their statement.
Nevertheless, the FDA used its emergency authority—for only the second time ever—to permit the use of hydroxychloroquine for COVID-19 in situations where clinical trials are unavailable or not feasible.
While no effective therapy exists yet for COVID-19, the authors of the veterans study are optimistic that already approved drugs are a suitable option.
“Given the longer development, testing, and approval times for novel chemical entities, repurposing drugs already approved for other indications is a promising approach to rapidly identify an effective therapy,” the authors write. “[Our] findings highlight the importance of awaiting the results of ongoing prospective, randomized, controlled studies before widespread adoption of these drugs. Until then, the findings from this retrospective study suggest caution in using hydroxychloroquine in hospitalized Covid-19 patients, particularly when not combined with azithromycin.”